Omega-3 Increase Good Cholesterol and Prevent Atherosclerosis

Eating fish rich in Omega-3, combined with blueberries and whole grains, positively affects fat metabolism in people with metabolic syndrome. In particular, an increased fish intake corresponds to larger HDL particles, which carry the so-called "good cholesterol," helping to counteract atherosclerosis.

This is reported by a study conducted at the University of Eastern Finland and published in the journal Plos One, aimed at evaluating the effect of a typical Nordic diet on lipid metabolism.

Lipoproteins

Within the body, cholesterol and triglycerides obtained from food are incorporated into structures called lipoproteins to be distributed to tissues via the bloodstream. These are classified as very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). The latter collect cholesterol from blood vessels and transport it back to the liver. HDL cholesterol is also known as "good cholesterol." LDL, on the other hand, can deposit fat on the walls of blood vessels, leading to atherosclerosis. The so-called "bad cholesterol" causes vessel narrowing, increasing the risk of heart attacks and strokes.

Larger HDL Particles with Omega-3

For the study, the team recruited 131 people aged between 40 and 70 years with impaired glucose metabolism and typical features of metabolic syndrome, such as high blood sugar, hypertension, and elevated triglycerides. Participants were divided into three groups. The first group replaced their usual wheat-based foods with whole grain and low glycemic index products and consumed 3 portions of fatty fish and 3 portions of blueberries per week. The second group received whole grain and low glycemic index foods but maintained their usual fish and berry consumption. The third group, the control group, consumed refined wheat bakery products and bread and ate no more than one portion of fish per week. After 12 weeks, researchers analyzed each patient’s metabolic characteristics, observing an increase in polyunsaturated fatty acids in the blood, particularly Omega-3, in the first group. Comparing subjects, the first group showed larger HDL particle size than the other two groups. Specifically, increased fish consumption was associated with a higher number of larger-diameter HDL particles compared to the average. The research team noted that larger HDL particles were linked to a lower risk of cardiovascular diseases, while smaller ones seemed to have the opposite effect.

Fatty Fish Helps Combat Atherosclerosis

The results suggest that following a diet rich in whole grains, blueberries, and especially fatty fish changes HDL composition by increasing the larger particles. These changes may be related to the protective functions of HDL, such as reverse cholesterol transport, and could partly explain the protective effects of fish consumption against atherosclerosis.

Source: Maria Lankinen, Marjukka Kolehmainen, Tiina Jääskeläinen, Jussi Paananen, Laura Joukamo, Antti J. Kangas, Pasi Soininen, Kaisa Poutanen, Hannu Mykkänen, Helena Gylling, Matej Orešič, Matti Jauhiainen, Mika Ala-Korpela, Ursula Schwab. “Effects of Whole Grain, Fish and Bilberries on Serum Metabolic Profile and Lipid Transfer Protein Activities: A Randomized Trial (Sysdimet)” February 28, 2014. DOI: 10.1371/journal.pone.0090352.